The subject invention is directed toward a rotor tiller having a counter-rotating twin shaft system. This new design eliminates many problems associated with conventional tillers and increases the utility of the subject tiller.
Conventional rotor tillers used for tilling soil and cultivating in gardening or agriculture works characteristically have a single shaft with a plurality of tines, usually four, affixed to it. In operation, the engine drives the shaft and its tines to rotate in unison in one direction, either clockwise or counter-clockwise and will till the ground while propelling the rotor tiller forward or backward.
These conventional, single shaft machines will do a good job of tilling previously tilled soil or light sandy soil. On hard soils, or rocky grounds however, conventional rotor tiller of any type becomes less efficient because the force required to till the hard ground exceeds the force exerted on the ground by the weight of the machine. Consequently, the machine will "walk" over the ground and skip spots, resulting in uneven tilling of the ground and also to a very shallow depth.
This problem is partially circumvented by installing a drag bar system or counter-rotating traction wheel which has the net effect of slowing the advance of the machine so that the tines can stay on a given spot longer, allowing deeper penetration of the tines into the soil. However, neither the drag bar system not the counter-rotating wheel by itself produces any useful work other than holding the machine back from advancing too quickly and the problem of uneven and shallow tilling remains, although somewhat diminished.
Secondly, to generate counter-rotating traction, special traction wheels and gear transmission have to be used and frequent switching between transmissions is required. Thirdly, on tilling hard soil, the motion of the tines often overpowered the stopping force of the drag bar or the traction of the counter-rotating wheels; this results in uncontrollable back and forth jerking motions of the machine and uneven tilling of the soil. In order to smooth the advance of the machine on hard soil surfaces, the operator has to pull and shove the machine forwardly and backwardly, causing human fatigue.
Fourthly, soil, especially hard soil dug up by the tines of conventional rotor tiller is in large chunks (held together by roots, grass etc.) that often requires further breaking apart either manually or by running the chunks of soil over and over with the machine in order to achieve a fine consistency. Finally, roots, vines, plastic sheets, cloths, ropes and other fabric like material etc. are often picked up by the blades and winds around the rotating shaft and tines. These tangling mass of non-soil materials can overload the engine and greatly reduce the digging power of the machine.
Besides the problems mentioned above, typically all conventional rotor tillers are designed for one single purpose such as tilling of the ground. Clearly, there is a need for a more efficient machine that is not only devoid of problems associated with the conventional rotor tillers, but is more versatile capable of tilling the ground in the spring and removal of snow in the winter.